Display panel or portion thereof with a transitional graphical user interface



FIG. 1 is a front view of a display panel or portion thereof with a transitional graphical user interface, showing a first image in a sequence for the new design;

FIG. 2 is a second image thereof;

FIG. 3 is a third image thereof;

FIG. 4 is a fourth image thereof;

FIG. 5 is a fifth image thereof;

FIG. 6 is a sixth image thereof;

FIG. 7 is a seventh image thereof;

FIG. 8 is an eighth image thereof;

FIG. 9 is a ninth image thereof;

FIG. 10 is a tenth image thereof;

FIG. 11 is an eleventh image thereof;

FIG. 12 is a twelfth image thereof;

FIG. 13 is a thirteenth image thereof;

FIG. 14 is a fourteenth image thereof;

FIG. 15 is a fifteenth image thereof;

FIG. 16 is a sixteenth image thereof;

FIG. 17 is a seventeenth image thereof;

FIG. 18 is an eighteenth image thereof;

FIG. 19 is a nineteenth image thereof; and,

FIG. 20 is a twentieth image thereof.

The appearance of the transitional image sequentially transitions between the images shown in FIGS. 1-20. The process or period in which one image transitions to another image forms no part of the claimed design.

The broken lines depicting a display panel or portion thereof are included for the purpose of illustrating portions of the article of manufacture and form no part of the claimed design. 

CLAIM The ornamental design for a display panel or portion thereof with a transitional graphical user interface, as shown and described. 